/*	$OpenBSD: rijndael.c,v 1.6 2000/12/09 18:51:34 markus Exp $ */

/* contrib/pgcrypto/rijndael.c */

/* This is an independent implementation of the encryption algorithm:	*/
/*																		*/
/*		   RIJNDAEL by Joan Daemen and Vincent Rijmen
 */
/*																		*/
/* which is a candidate algorithm in the Advanced Encryption Standard	*/
/* programme of the US National Institute of Standards and Technology.  */
/*																		*/
/* Copyright in this implementation is held by Dr B R Gladman but I
 */
/* hereby give permission for its free direct or derivative use subject */
/* to acknowledgment of its origin and compliance with any conditions	*/
/* that the originators of the algorithm place on its exploitation.     */
/*																		*/
/* Dr Brian Gladman (gladman@seven77.demon.co.uk) 14th January 1999
 */

/* Timing data for Rijndael (rijndael.c)

Algorithm: rijndael (rijndael.c)

128 bit key:
Key Setup:	  305/1389 cycles (encrypt/decrypt)
Encrypt:	   374 cycles =    68.4 mbits/sec
Decrypt:	   352 cycles =    72.7 mbits/sec
Mean:		   363 cycles =    70.5 mbits/sec

192 bit key:
Key Setup:	  277/1595 cycles (encrypt/decrypt)
Encrypt:	   439 cycles =    58.3 mbits/sec
Decrypt:	   425 cycles =    60.2 mbits/sec
Mean:		   432 cycles =    59.3 mbits/sec

256 bit key:
Key Setup:	  374/1960 cycles (encrypt/decrypt)
Encrypt:	   502 cycles =    51.0 mbits/sec
Decrypt:	   498 cycles =    51.4 mbits/sec
Mean:		   500 cycles =    51.2 mbits/sec

*/

#include <ccoin/crypto/rijndael.h> // for u4byte, u1byte, etc

#include <stdint.h> // for uint32_t, uint8_t
#include <string.h> // for memcpy

#define PRE_CALC_TABLES
#define LARGE_TABLES

static void gen_tabs(void);

/* 3. Basic macros for speeding up generic operations */

/* Circular rotate of 32 bit values
 */

#define rotr(x, n) (((x) >> ((int)(n))) | ((x) << (32 - (int)(n))))
#define rotl(x, n) (((x) << ((int)(n))) | ((x) >> (32 - (int)(n))))

/* Invert byte order in a 32 bit variable
 */

#define bswap(x) ((rotl((x), 8) & 0x00ff00ff) | (rotr((x), 8) & 0xff00ff00))

/* Extract byte from a 32 bit quantity (little endian notation)		*/

#define byte(x, n) ((u1byte)((x) >> (8 * (n))))

#ifdef WORDS_BIGENDIAN
#define io_swap(x) bswap(x)
#else
#define io_swap(x) (x)
#endif

#ifdef PRINT_TABS
#undef PRE_CALC_TABLES
#endif

#ifdef PRE_CALC_TABLES

#include <ccoin/crypto/rijndael.tbl> // for ft_tab, it_tab, fl_tab, etc
#define tab_gen 1
#else /* !PRE_CALC_TABLES */

static u1byte pow_tab[256];
static u1byte log_tab[256];
static u1byte sbx_tab[256];
static u1byte isb_tab[256];
static u4byte rco_tab[10];
static u4byte ft_tab[4][256];
static u4byte it_tab[4][256];

#ifdef LARGE_TABLES
static u4byte fl_tab[4][256];
static u4byte il_tab[4][256];
#endif

static u4byte tab_gen = 0;
#endif /* !PRE_CALC_TABLES */

#define ff_mult(a, b)                                                          \
    ((a) && (b) ? pow_tab[(log_tab[a] + log_tab[b]) % 255] : 0)

#define f_rn(bo, bi, n, k)                                                     \
    (bo)[n] = ft_tab[0][byte((bi)[n], 0)] ^                                    \
              ft_tab[1][byte((bi)[((n) + 1) & 3], 1)] ^                        \
              ft_tab[2][byte((bi)[((n) + 2) & 3], 2)] ^                        \
              ft_tab[3][byte((bi)[((n) + 3) & 3], 3)] ^ *((k) + (n))

#define i_rn(bo, bi, n, k)                                                     \
    (bo)[n] = it_tab[0][byte((bi)[n], 0)] ^                                    \
              it_tab[1][byte((bi)[((n) + 3) & 3], 1)] ^                        \
              it_tab[2][byte((bi)[((n) + 2) & 3], 2)] ^                        \
              it_tab[3][byte((bi)[((n) + 1) & 3], 3)] ^ *((k) + (n))

#ifdef LARGE_TABLES

#define ls_box(x)                                                              \
    (fl_tab[0][byte(x, 0)] ^ fl_tab[1][byte(x, 1)] ^ fl_tab[2][byte(x, 2)] ^   \
     fl_tab[3][byte(x, 3)])

#define f_rl(bo, bi, n, k)                                                     \
    (bo)[n] = fl_tab[0][byte((bi)[n], 0)] ^                                    \
              fl_tab[1][byte((bi)[((n) + 1) & 3], 1)] ^                        \
              fl_tab[2][byte((bi)[((n) + 2) & 3], 2)] ^                        \
              fl_tab[3][byte((bi)[((n) + 3) & 3], 3)] ^ *((k) + (n))

#define i_rl(bo, bi, n, k)                                                     \
    (bo)[n] = il_tab[0][byte((bi)[n], 0)] ^                                    \
              il_tab[1][byte((bi)[((n) + 3) & 3], 1)] ^                        \
              il_tab[2][byte((bi)[((n) + 2) & 3], 2)] ^                        \
              il_tab[3][byte((bi)[((n) + 1) & 3], 3)] ^ *((k) + (n))
#else

#define ls_box(x)                                                              \
    ((u4byte)sbx_tab[byte(x, 0)] << 0) ^ ((u4byte)sbx_tab[byte(x, 1)] << 8) ^  \
        ((u4byte)sbx_tab[byte(x, 2)] << 16) ^                                  \
        ((u4byte)sbx_tab[byte(x, 3)] << 24)

#define f_rl(bo, bi, n, k)                                                     \
    (bo)[n] = (u4byte)sbx_tab[byte((bi)[n], 0)] ^                              \
              rotl(((u4byte)sbx_tab[byte((bi)[((n) + 1) & 3], 1)]), 8) ^       \
              rotl(((u4byte)sbx_tab[byte((bi)[((n) + 2) & 3], 2)]), 16) ^      \
              rotl(((u4byte)sbx_tab[byte((bi)[((n) + 3) & 3], 3)]), 24) ^      \
              *((k) + (n))

#define i_rl(bo, bi, n, k)                                                     \
    (bo)[n] = (u4byte)isb_tab[byte((bi)[n], 0)] ^                              \
              rotl(((u4byte)isb_tab[byte((bi)[((n) + 3) & 3], 1)]), 8) ^       \
              rotl(((u4byte)isb_tab[byte((bi)[((n) + 2) & 3], 2)]), 16) ^      \
              rotl(((u4byte)isb_tab[byte((bi)[((n) + 1) & 3], 3)]), 24) ^      \
              *((k) + (n))
#endif

static void gen_tabs(void) {
#ifndef PRE_CALC_TABLES
    u4byte i, t;
    u1byte p, q;

    /* log and power tables for GF(2**8) finite field with	*/
    /* 0x11b as modular polynomial - the simplest prmitive	*/
    /* root is 0x11, used here to generate the tables		*/

    for (i = 0, p = 1; i < 256; ++i) {
        pow_tab[i] = (u1byte)p;
        log_tab[p] = (u1byte)i;

        p = p ^ (p << 1) ^ (p & 0x80 ? 0x01b : 0);
    }

    log_tab[1] = 0;
    p = 1;

    for (i = 0; i < 10; ++i) {
        rco_tab[i] = p;

        p = (p << 1) ^ (p & 0x80 ? 0x1b : 0);
    }

    /* note that the affine byte transformation matrix in	*/
    /* rijndael specification is in big endian format with	*/
    /* bit 0 as the most significant bit. In the remainder	*/
    /* of the specification the bits are numbered from the	*/
    /* least significant end of a byte.                     */

    for (i = 0; i < 256; ++i) {
        p = (i ? pow_tab[255 - log_tab[i]] : 0);
        q = p;
        q = (q >> 7) | (q << 1);
        p ^= q;
        q = (q >> 7) | (q << 1);
        p ^= q;
        q = (q >> 7) | (q << 1);
        p ^= q;
        q = (q >> 7) | (q << 1);
        p ^= q ^ 0x63;
        sbx_tab[i] = (u1byte)p;
        isb_tab[p] = (u1byte)i;
    }

    for (i = 0; i < 256; ++i) {
        p = sbx_tab[i];

#ifdef LARGE_TABLES

        t = p;
        fl_tab[0][i] = t;
        fl_tab[1][i] = rotl(t, 8);
        fl_tab[2][i] = rotl(t, 16);
        fl_tab[3][i] = rotl(t, 24);
#endif
        t = ((u4byte)ff_mult(2, p)) | ((u4byte)p << 8) | ((u4byte)p << 16) |
            ((u4byte)ff_mult(3, p) << 24);

        ft_tab[0][i] = t;
        ft_tab[1][i] = rotl(t, 8);
        ft_tab[2][i] = rotl(t, 16);
        ft_tab[3][i] = rotl(t, 24);

        p = isb_tab[i];

#ifdef LARGE_TABLES

        t = p;
        il_tab[0][i] = t;
        il_tab[1][i] = rotl(t, 8);
        il_tab[2][i] = rotl(t, 16);
        il_tab[3][i] = rotl(t, 24);
#endif
        t = ((u4byte)ff_mult(14, p)) | ((u4byte)ff_mult(9, p) << 8) |
            ((u4byte)ff_mult(13, p) << 16) | ((u4byte)ff_mult(11, p) << 24);

        it_tab[0][i] = t;
        it_tab[1][i] = rotl(t, 8);
        it_tab[2][i] = rotl(t, 16);
        it_tab[3][i] = rotl(t, 24);
    }

    tab_gen = 1;
#endif /* !PRE_CALC_TABLES */
}

#define star_x(x) (((x)&0x7f7f7f7f) << 1) ^ ((((x)&0x80808080) >> 7) * 0x1b)

#define imix_col(y, x)                                                         \
    do {                                                                       \
        u = star_x(x);                                                         \
        v = star_x(u);                                                         \
        w = star_x(v);                                                         \
        t = w ^ (x);                                                           \
        (y) = u ^ v ^ w;                                                       \
        (y) ^= rotr(u ^ t, 8) ^ rotr(v ^ t, 16) ^ rotr(t, 24);                 \
    } while (0)

/* initialise the key schedule from the user supplied key	*/

#define loop4(i)                                                               \
    do {                                                                       \
        t = ls_box(rotr(t, 8)) ^ rco_tab[i];                                   \
        t ^= e_key[4 * i];                                                     \
        e_key[4 * i + 4] = t;                                                  \
        t ^= e_key[4 * i + 1];                                                 \
        e_key[4 * i + 5] = t;                                                  \
        t ^= e_key[4 * i + 2];                                                 \
        e_key[4 * i + 6] = t;                                                  \
        t ^= e_key[4 * i + 3];                                                 \
        e_key[4 * i + 7] = t;                                                  \
    } while (0)

#define loop6(i)                                                               \
    do {                                                                       \
        t = ls_box(rotr(t, 8)) ^ rco_tab[i];                                   \
        t ^= e_key[6 * (i)];                                                   \
        e_key[6 * (i) + 6] = t;                                                \
        t ^= e_key[6 * (i) + 1];                                               \
        e_key[6 * (i) + 7] = t;                                                \
        t ^= e_key[6 * (i) + 2];                                               \
        e_key[6 * (i) + 8] = t;                                                \
        t ^= e_key[6 * (i) + 3];                                               \
        e_key[6 * (i) + 9] = t;                                                \
        t ^= e_key[6 * (i) + 4];                                               \
        e_key[6 * (i) + 10] = t;                                               \
        t ^= e_key[6 * (i) + 5];                                               \
        e_key[6 * (i) + 11] = t;                                               \
    } while (0)

#define loop8(i)                                                               \
    do {                                                                       \
        t = ls_box(rotr(t, 8)) ^ rco_tab[i];                                   \
        t ^= e_key[8 * (i)];                                                   \
        e_key[8 * (i) + 8] = t;                                                \
        t ^= e_key[8 * (i) + 1];                                               \
        e_key[8 * (i) + 9] = t;                                                \
        t ^= e_key[8 * (i) + 2];                                               \
        e_key[8 * (i) + 10] = t;                                               \
        t ^= e_key[8 * (i) + 3];                                               \
        e_key[8 * (i) + 11] = t;                                               \
        t = e_key[8 * (i) + 4] ^ ls_box(t);                                    \
        e_key[8 * (i) + 12] = t;                                               \
        t ^= e_key[8 * (i) + 5];                                               \
        e_key[8 * (i) + 13] = t;                                               \
        t ^= e_key[8 * (i) + 6];                                               \
        e_key[8 * (i) + 14] = t;                                               \
        t ^= e_key[8 * (i) + 7];                                               \
        e_key[8 * (i) + 15] = t;                                               \
    } while (0)

rijndael_ctx *rijndael_set_key(rijndael_ctx *ctx, const u4byte *in_key,
                               const u4byte key_len, int encrypt) {
    u4byte i, t, u, v, w;
    u4byte *e_key = ctx->e_key;
    u4byte *d_key = ctx->d_key;

    ctx->decrypt = !encrypt;

    if (!tab_gen)
        gen_tabs();

    ctx->k_len = (key_len + 31) / 32;

    e_key[0] = io_swap(in_key[0]);
    e_key[1] = io_swap(in_key[1]);
    e_key[2] = io_swap(in_key[2]);
    e_key[3] = io_swap(in_key[3]);

    switch (ctx->k_len) {
    case 4:
        t = e_key[3];
        for (i = 0; i < 10; ++i)
            loop4(i);
        break;

    case 6:
        e_key[4] = io_swap(in_key[4]);
        t = e_key[5] = io_swap(in_key[5]);
        for (i = 0; i < 8; ++i)
            loop6(i);
        break;

    case 8:
        e_key[4] = io_swap(in_key[4]);
        e_key[5] = io_swap(in_key[5]);
        e_key[6] = io_swap(in_key[6]);
        t = e_key[7] = io_swap(in_key[7]);
        for (i = 0; i < 7; ++i)
            loop8(i);
        break;
    }

    if (!encrypt) {
        d_key[0] = e_key[0];
        d_key[1] = e_key[1];
        d_key[2] = e_key[2];
        d_key[3] = e_key[3];

        for (i = 4; i < 4 * ctx->k_len + 24; ++i)
            imix_col(d_key[i], e_key[i]);
    }

    return ctx;
}

/* encrypt a block of text	*/

#define f_nround(bo, bi, k)                                                    \
    do {                                                                       \
        f_rn(bo, bi, 0, k);                                                    \
        f_rn(bo, bi, 1, k);                                                    \
        f_rn(bo, bi, 2, k);                                                    \
        f_rn(bo, bi, 3, k);                                                    \
        k += 4;                                                                \
    } while (0)

#define f_lround(bo, bi, k)                                                    \
    do {                                                                       \
        f_rl(bo, bi, 0, k);                                                    \
        f_rl(bo, bi, 1, k);                                                    \
        f_rl(bo, bi, 2, k);                                                    \
        f_rl(bo, bi, 3, k);                                                    \
    } while (0)

void rijndael_encrypt(rijndael_ctx *ctx, const u4byte *in_blk,
                      u4byte *out_blk) {
    u4byte k_len = ctx->k_len;
    u4byte *e_key = ctx->e_key;
    u4byte b0[4], b1[4], *kp;

    b0[0] = io_swap(in_blk[0]) ^ e_key[0];
    b0[1] = io_swap(in_blk[1]) ^ e_key[1];
    b0[2] = io_swap(in_blk[2]) ^ e_key[2];
    b0[3] = io_swap(in_blk[3]) ^ e_key[3];

    kp = e_key + 4;

    if (k_len > 6) {
        f_nround(b1, b0, kp);
        f_nround(b0, b1, kp);
    }

    if (k_len > 4) {
        f_nround(b1, b0, kp);
        f_nround(b0, b1, kp);
    }

    f_nround(b1, b0, kp);
    f_nround(b0, b1, kp);
    f_nround(b1, b0, kp);
    f_nround(b0, b1, kp);
    f_nround(b1, b0, kp);
    f_nround(b0, b1, kp);
    f_nround(b1, b0, kp);
    f_nround(b0, b1, kp);
    f_nround(b1, b0, kp);
    f_lround(b0, b1, kp);

    out_blk[0] = io_swap(b0[0]);
    out_blk[1] = io_swap(b0[1]);
    out_blk[2] = io_swap(b0[2]);
    out_blk[3] = io_swap(b0[3]);
}

/* decrypt a block of text	*/

#define i_nround(bo, bi, k)                                                    \
    do {                                                                       \
        i_rn(bo, bi, 0, k);                                                    \
        i_rn(bo, bi, 1, k);                                                    \
        i_rn(bo, bi, 2, k);                                                    \
        i_rn(bo, bi, 3, k);                                                    \
        k -= 4;                                                                \
    } while (0)

#define i_lround(bo, bi, k)                                                    \
    do {                                                                       \
        i_rl(bo, bi, 0, k);                                                    \
        i_rl(bo, bi, 1, k);                                                    \
        i_rl(bo, bi, 2, k);                                                    \
        i_rl(bo, bi, 3, k);                                                    \
    } while (0)

void rijndael_decrypt(rijndael_ctx *ctx, const u4byte *in_blk,
                      u4byte *out_blk) {
    u4byte b0[4], b1[4], *kp;
    u4byte k_len = ctx->k_len;
    u4byte *e_key = ctx->e_key;
    u4byte *d_key = ctx->d_key;

    b0[0] = io_swap(in_blk[0]) ^ e_key[4 * k_len + 24];
    b0[1] = io_swap(in_blk[1]) ^ e_key[4 * k_len + 25];
    b0[2] = io_swap(in_blk[2]) ^ e_key[4 * k_len + 26];
    b0[3] = io_swap(in_blk[3]) ^ e_key[4 * k_len + 27];

    kp = d_key + 4 * (k_len + 5);

    if (k_len > 6) {
        i_nround(b1, b0, kp);
        i_nround(b0, b1, kp);
    }

    if (k_len > 4) {
        i_nround(b1, b0, kp);
        i_nround(b0, b1, kp);
    }

    i_nround(b1, b0, kp);
    i_nround(b0, b1, kp);
    i_nround(b1, b0, kp);
    i_nround(b0, b1, kp);
    i_nround(b1, b0, kp);
    i_nround(b0, b1, kp);
    i_nround(b1, b0, kp);
    i_nround(b0, b1, kp);
    i_nround(b1, b0, kp);
    i_lround(b0, b1, kp);

    out_blk[0] = io_swap(b0[0]);
    out_blk[1] = io_swap(b0[1]);
    out_blk[2] = io_swap(b0[2]);
    out_blk[3] = io_swap(b0[3]);
}

/*
 * conventional interface
 *
 * ATM it hopes all data is 4-byte aligned - which
 * should be true for PRNG.  -marko
 */

void aes_set_key(rijndael_ctx *ctx, const uint8_t *key, unsigned keybits,
                 int enc) {
    uint32_t *k;

    k = (uint32_t *)key;
    rijndael_set_key(ctx, k, keybits, enc);
}

void aes_ecb_encrypt(rijndael_ctx *ctx, uint8_t *data, unsigned len) {
    unsigned bs = 16;
    uint32_t *d;

    while (len >= bs) {
        d = (uint32_t *)data;
        rijndael_encrypt(ctx, d, d);

        len -= bs;
        data += bs;
    }
}

void aes_ecb_decrypt(rijndael_ctx *ctx, uint8_t *data, unsigned len) {
    unsigned bs = 16;
    uint32_t *d;

    while (len >= bs) {
        d = (uint32_t *)data;
        rijndael_decrypt(ctx, d, d);

        len -= bs;
        data += bs;
    }
}

void aes_cbc_encrypt(rijndael_ctx *ctx, uint8_t *iva, uint8_t *data,
                     unsigned len) {
    uint32_t *iv = (uint32_t *)iva;
    uint32_t *d = (uint32_t *)data;
    unsigned bs = 16;

    while (len >= bs) {
        d[0] ^= iv[0];
        d[1] ^= iv[1];
        d[2] ^= iv[2];
        d[3] ^= iv[3];

        rijndael_encrypt(ctx, d, d);

        iv = d;
        d += bs / 4;
        len -= bs;
    }
}

void aes_cbc_decrypt(rijndael_ctx *ctx, uint8_t *iva, uint8_t *data,
                     unsigned len) {
    uint32_t *d = (uint32_t *)data;
    unsigned bs = 16;
    uint32_t buf[4], iv[4];

    memcpy(iv, iva, bs);
    while (len >= bs) {
        buf[0] = d[0];
        buf[1] = d[1];
        buf[2] = d[2];
        buf[3] = d[3];

        rijndael_decrypt(ctx, buf, d);

        d[0] ^= iv[0];
        d[1] ^= iv[1];
        d[2] ^= iv[2];
        d[3] ^= iv[3];

        iv[0] = buf[0];
        iv[1] = buf[1];
        iv[2] = buf[2];
        iv[3] = buf[3];
        d += 4;
        len -= bs;
    }
}

/*
 * pre-calculate tables.
 *
 * On i386 lifts 17k from .bss to .rodata
 * and avoids 1k code and setup time.
 *	  -marko
 */
#ifdef PRINT_TABS

static void show256u8(char *name, uint8_t *data) {
    int i;

    printf("static const u1byte  %s[256] = {\n  ", name);
    for (i = 0; i < 256;) {
        printf("%u", pow_tab[i++]);
        if (i < 256)
            printf(i % 16 ? ", " : ",\n  ");
    }
    printf("\n};\n\n");
}

static void show4x256u32(char *name, uint32_t data[4][256]) {
    int i, j;

    printf("static const u4byte  %s[4][256] = {\n{\n  ", name);
    for (i = 0; i < 4; i++) {
        for (j = 0; j < 256;) {
            printf("0x%08x", data[i][j]);
            j++;
            if (j < 256)
                printf(j % 4 ? ", " : ",\n  ");
        }
        printf(i < 3 ? "\n}, {\n  " : "\n}\n");
    }
    printf("};\n\n");
}

int main() {
    int i;
    char *hdr = "/* Generated by rijndael.c */\n\n";

    gen_tabs();

    printf(hdr);
    show256u8("pow_tab", pow_tab);
    show256u8("log_tab", log_tab);
    show256u8("sbx_tab", sbx_tab);
    show256u8("isb_tab", isb_tab);

    show4x256u32("ft_tab", ft_tab);
    show4x256u32("it_tab", it_tab);
#ifdef LARGE_TABLES
    show4x256u32("fl_tab", fl_tab);
    show4x256u32("il_tab", il_tab);
#endif
    printf("static const u4byte rco_tab[10] = {\n  ");
    for (i = 0; i < 10; i++) {
        printf("0x%08x", rco_tab[i]);
        if (i < 9)
            printf(", ");
        if (i == 4)
            printf("\n  ");
    }
    printf("\n};\n\n");
    return 0;
}

#endif
